The Pringle maneuver (PM) is recognized in conventional liver surgery as a method of controlling bleeding. To determine the hemodynamic effects of the PM during pneumoperitoneum (PP) for laparoscopic liver resection, we measured hemodynamic and blood gas changes in 7 healthy pigs. All variables were recorded 5 min before and 10 and 30 min after employing PP or PM and 10 min after discontinuation of PM. After the induction of PP, cardiac index and arterial carbon dioxide tension significantly increased, accompanied by a significant decrease in pH. After the beginning of PM, cardiac index and mean arterial and central venous presures decreased significantly, whereas the heart rate rose markedly. After discontinuation of the PM, the systemic vascular resistance index decreased, and the heart rate remained elevated. These results demonstrate severe hemodynamic deterioration with PP and a subsequent PM. The latter should, therefore, be considered only as a last resort for the control of bleeding during laparoscopic liver surgery.